1. Field of the Invention
The present invention relates to a recovery processing method for a print head configured to perform a print operation by ejecting ink, and to an ink jet printing apparatus using the same.
2. Description of the Related Art
An inkjet printing apparatus configured to perform a print operation by ejecting ink onto a print surface of a print medium comprises a recovery processor, for example, as a measure for keeping normal ink ejection from ink ejection openings of a print head. The recovery processor performs the recovery processing for each of print heads of a print section.
It is known that such recovery processors configured to perform a sucking operation, a wiping operation, preliminary ejection (an operation to eject ink from ink ejection openings when a wiper used for the wiping operation passes over the ink ejection openings) (hereinafter referred to as preliminary ejection), a heating operation, and other operations. The recovery processor causes viscosity ink, minute air bubbles, and the like inside the print head to surely discharge to the outside, and also causes foreign objects, ink mist, and the like which adhere to an ink ejection opening forming surface on which the ink ejection openings of the print head are formed to remove.
As shown in Japanese Patent Laid-Open No. S59-045161 (1984) and H07-148934 (1995), for example, a technique widely used in the wiping operation is to clean the ink ejection opening forming surface by use of the wiper when a certain condition is met. The case where the certain condition is met may be after ejection of the ink from the print head, after a lapse of a predetermined period without use of the print head, or after execution of the sucking operation, for example.
This enables performance of an inkjet head which serves as liquid ejecting means mounted in an inkjet printing apparatus as a liquid ejecting apparatus to maintain. In this case, it has also been proposed to apply the above-described technique of preliminary ejection in order to improve the cleaning performance with the wiper and to remove the viscosity ink and paper fluff (dust) adhering to the ink ejection opening forming surface.
For example, Japanese Patent Laid-Open No. S59-045161 (1984) discloses a method of preventing drying at ink ejection openings of a print head, interfusion of bubbles, and clogging ejection opening (which are referred to as nozzles in Japanese Patent Laid-Open No. S59-045161 (1984)) of the ink ejection openings. According to this method, in a wiping operation in an arrangement direction of multiple ink ejection openings of a print head by a cleaner, the cleaner performs cleaning by scrubbing a tip end surface of the ink ejection opening of the print head where the ink ejection openings are formed, while the ink is ejected from the ink ejection openings to be used for image formation or the other ink ejection opening not to be used for image formation (recording or printing for character formation or the like). In this way, the tip end surface is cleaned while sweeping the ink thereon. As a result, there is an effect of removing the ink having relatively high viscosity which adheres to the tip end surface where the ink ejection openings are formed.
Meanwhile, Japanese Patent Laid-Open No. H07-148934 (1995) discloses a maintenance method for an inkjet print head for preventing occurrence of clogging at ink ejection openings of a print head after disuse for a long time. According to this method, a print head is moved to a wiper and is cause to eject ink from ink ejection openings onto the wiper. Then, accumulated ink is wiped off a nozzle plate with the wet wiper.
Moreover, in Japanese Patent Laid-Open No. H 11-342620 (1999), there has been proposal for a method of moistening an ink ejection opening forming surface of a print head before and during a wiping operation using a wiper when the wiper wipes the ink ejection opening forming surface of the print head in a direction perpendicular to the arrangement direction of ink ejection openings. This method makes it easier to remove the ink adhering to the ink ejection opening forming surface because ink from the print head adheres not only to a leading surface of a wiper blade but also to a leading edge region and a tailing edge region of the print head. Thus, wiping in combination with ink ejection leads to improvement in stain removal performance.